As Ontario continues to address the housing crisis, big changes are happening in small spaces—literally. Recent updates to the provincial regulations around Laneway Homes and Garden Suites (also known as Additional Residential Units or ARUs) are making it easier than ever for homeowners to build secondary dwellings on their property.

Whether you’re dreaming of a rental income stream, planning for multi-generational living, or simply looking to add value to your home, these regulation changes open the door to new possibilities.

A Quick Recap: Laneway & Garden Suites

Introduced in Toronto’s zoning by-laws in 2018 and 2022 respectively, laneway houses and garden suites are self-contained residential units located on the same lot as a detached, semi-detached, or townhouse.

They’re typically tucked away in the backyard or laneway, utilizing underused space to create much-needed housing while keeping the neighborhood’s character intact.

So, What’s New?

In a bold move to boost housing supply, the Province of Ontario has introduced changes that override local municipal by-laws, making it easier to design and build ARUs across the province. These updates simplify the planning process, reduce design constraints, and expand eligibility to more properties.

Let’s break down the key changes:

1. Goodbye, Angular Plane

Previously, secondary suites had to conform to a 45-degree angled roofline, which often compromised the design and layout of second floors. Now, angular plane requirements no longer apply to properties with 1 or 2 units in the main dwelling.

What this means: Designers and homeowners have more freedom to build full-height vertical walls right up to the roofline—no more sloped ceilings!

2. Increased Lot Coverage

The new regulations allow up to 45% lot coverage for properties with a laneway or garden suite.

What this means: More flexibility to add rear additions to the main house or build a larger ARU—without running into zoning headaches.

3. Minimum Lot Size? Not Anymore

Forget the minimum lot size restrictions—if you have a legal lot, you’re good to go.

What this means: Smaller lots, which were previously excluded, are now eligible for garden or laneway suites. More Torontonians can now take advantage of this opportunity.

4. Floor Space Index (FSI) Limits Removed

The FSI—formerly used to limit total building size on a lot—is no longer a barrier when adding an ARU, as long as setback and height rules are met.

What this means: Bigger suites are now possible. For instance, a property that was previously capped at 0.6 FSI can now maximize its footprint without restriction—great for livability and design flexibility.

5. Closer to Home: Reduced Separation Distance

The required distance between the ARU and the main home has been reduced to just 4 metres (down from 5–7.5m, depending on height).

What this means: Even tight backyards can now accommodate a suite. This change dramatically increases the number of eligible properties, especially in dense urban areas.

What This Means for You (and for the City)

With these updated rules, up to 80% of Toronto homes could now support a laneway or garden suite. That’s a game-changer for homeowners and for the city as a whole. These changes lower the cost, reduce timelines, and expand eligibility—making it easier to increase density while preserving neighborhood character.

More importantly, this is a crucial step toward building a more sustainable and inclusive city.

Ready to Build Your Suite?

As architects, we’re thrilled to see these updates—and we’re here to help bring your vision to life. Whether you’re in the early stages of exploring possibilities or ready to submit a permit application, we’ll guide you through the process and design a space that works for your goals and your lot.

Get in touch to learn more or visit Garden Suites – City of Toronto  for further details.